1. Field of the Invention
The present invention relates to gripping devices for automatic bottle-topping machines. More precisely, the present invention regards a gripping device designed for installation on a carousel of an automatic bottle-topping machine and designed to withhold a bottle.
2. Description of the Related Art
Automatic bottle-topping machines have, in general, a carousel structure comprising a plurality of different devices, each designed to perform a particular function. Amongst said devices, for example, are topping devices and gripping devices.
Designated by 1 in FIG. 1 is an automatic bottle-topping machine of a known type. The machine 1 has a vertical axis X about which a plurality of carousels turn, said machine comprising a bottle-holder carousel designated by 2 in FIG. 1. The bottle-holder carousel 2 comprises a central star 4, an external guide element 6, and a gripping structure 8.
The gripping structure 8 comprises a plurality of gripping devices 10. Each gripping device 10 comprises an external guide element 12 and an internal centring and blocking element 14.
A plurality of bottles 16 is carried by the bottle-holder carousel 2 so that the body of the bottles is set in compartments created by the central star 4 and by the external guide element 6, whilst the neck of the bottles is set between the blocking element 14 and the guide element 12.
With reference to FIG. 1a, which illustrates at an enlarged scale a detail indicated by an arrow I in FIG. 1, each centring and blocking element 14 has a bent lip with a toothed edge 18, which is designed to penetrate in a lip 20 of each bottle 16. The machine 1 further comprises a plurality of topping devices 22, particularly of the type with screwing head, positioned so as to be coaxial to a corresponding bottle 16 carried by the bottle-holder carousel 2.
During operation of the machine 1, the bottle-holder carousel 2 turns about the axis X and draws the bottles 16 in rotation. The topping devices 22 turn together with the machine 1 and do not vary their relative position with respect to the corresponding bottles 16.
Each topping device 22 descends towards the corresponding bottle 16 and screws a threaded top or cap on the neck thereof. In order to keep the bottle 16 fixed in rotation during screwing, the toothed edge 18 penetrates within the lip 20 following upon a vertical load, directed parallel to the axis X, applied on the bottles 16 by the corresponding topping devices 22.
The above process, however, exerts a stress on the thread present in the top, as well as on the lip 20 of the bottle and moreover, since the gripping devices 10 are not able to ensure, by themselves, positioning of the bottle, imposes the need to use the central star 4 and the external guide element 6. Whenever it is necessary to process bottles of different formats it becomes necessary to replace the parts 4 and 6, which increases the number of central stars and external guide elements necessary for proper operation of the machine 1 and moreover creates delays in the production chain due to the times for tooling the machine 1.
The object of the present invention is to overcome the problems of the known art. In particular, the object of the present invention is to provide a gripping device that is able to block rotation of a bottle without exerting a stress on the lip and is able to eliminate the problems linked to the use of the central star and of the external guide element for guiding each bottle.